 .spinner 
    margin 100px auto
    widt 50px
    height 50px
    text-align center
    font-size 10px
    div 
        display inline-block
        width 5px
        height 100%
        background-color rgb(43, 128, 226)
        margin-right 1px
        animation bytedance 1s infinite
        for num in (2..5)
            &:nth-child({num})
                animation-delay (-0.9 + (num -2) * 0.1)s
  @keyframes bytedance
    0%, 40%, 100% 
        transform scaleY(0.4)
    
    20% 
        transform scaleY(1)
    
  